Moisture-free package



April 7, 1964 s. EGE

MOISTURE-FREE PACKAGE Filed May 29, 1962 F ig.

INVENTOR.

SIGMU N D EGE ///5 um K United States Patent O 3,128,135 MISTURE-FREE PACKAGE Sigmund Ege, Hastings 'on Hudson, NSY., assigner to Anaconda Wire and Cable Company Filed May 29, 1962, Ser. No. 198,560 7 Claims. (Cl. S12- 31) My invention relates to a package for material sensitive to moisture and particularly to a package for an oilsaturated cable core and to a method for making such a package.

In the manufacture of pipe-type cables, paper-wrapped cable cores are saturated with insulating oil, shipped to an installation site and pulled into a pipe that has been buried in the ground and will later be lled with oil or gas under pressure. In saturating the cores no care and expense is spared to remove all traces of moisture from the oil and from the saturated paper but it is necessary to package the cores on reels for shipment and to store the reeled cores for varying periods, both in the manufacturing plant and at the installation site. In order to prevent moisture contamination of the oil which has been so carefully freed from moisture it is known to seal the reels and to include a supply of a desiccant such as silica gel under the seal to absorb any moisture that might leak past the seal or be present in the air or on the surface of the cable during the reeling and packaging operation.

This known, conventional method of shipping and storing pipe-type cable cores has not provided the degree of dryness that is necessary to meet the demands of modern cables. This is due to the limitations of the desiccants that are suitable for packaging with cables. The nurnber of such drying agents is small. For one thing deliquescent salts cannot be used for fear of contaminating the cables with salt solution should the capacity of the desiccant ever be exceeded. As a matter of practicality only adsorption types of desiccants are suitable, and this accounts for the almost universal employment of silica gel. But silica gel, while it is a very eiiicient desiccant at high relative humidities, does not absorb much moisture at the low relative humidities to which modern cable cores are reduced. On the other hand desiccants such as molecular sieves which are very efficient at low humidities are extravagant to use in shipping packages where they will be discarded when the package is opened and not repeatedly regenerated. It is the fact that these expensive desiccants can be regenerated substantially without limit that has made it practical to use them in industry in spite of their high cost. It is not, however, a practical matter to regenerate the desiccants used for drying large cable-core packages, so that the high cost of molecular sieve has prevented its use for this purpose.

I have discovered that the advantages of high-efficiency drying agents can be obtained by making a package for shipping moisture sensitive material comprising a substantially moisture-tight covering surrounding the material, a quantity of a drying agent with a capacity less than by weight at 5% R.H. and 25 C., and a lesser quantity of another drying agent with a capacity greater than by Weight at 5% R.H. and 25 C. The higher capacity drying agent has a moisture-tight container and I provide a means for opening this container without removing the aforementioned moistureatight covering. In a preferred embodiment of my package I employ silica gel and crystalline aluminosilicate as drying agents.

When used for oil-saturated electric cable cores my package will comprise a flanged reel with a moisturetight cover sealing the space between the lianges. The crystalline aluminosilicate is conveniently enclosed in a container with a ripcord which passes through a perforation in the reel, such as in the flange of the reel, and means are provided for sealing the perforation.

Patented Apr. 7., 1964 ICC I have invented the method of preparing a moisture sensitive article such as an oil-saturated cable core for shipment by xing a substantially moisture-tight container of a rst drying agent having a high moisture capacity at low relative humidity to the article or cable core. Such a drying agent might have a capacity in excess of 15 by weight at 5% RII. and 25 C. I also fix a moisure permeable container of a second drying agent which has a moisture capacity at low relative humidity, low relative to the lirst drying agent, adjacent to the article. This drying agent might have a capacity less than 10% by weight at 5% RH. and 25 C. I then cover the article and containers with a substantially moisture-tight cover while providing means for opening the moisturetight container from the outside of said cover. In the case of a cable core, I iirst wind the core onto a flanged reel and cover the area between the flanges. My opening means may be a ripcord passing through a perforation in the reel in which case after opening the container I seal the perforation.

A more thorough understanding of my invention may be gained from a study of the appended drawing.

In the drawing:

FIGURE 1 is a vertical section of a package of my invention.

FIGURE 2 is a section through the plane 2-'2 of FIG- URE 1.

FIGURE 3 is a section of a drying agent container taken through the plane 3-3 of FIGURE 2.

Referring to FIGURE 1 a cable reel 11 having iianges 12, 13 and an imperforate drum 14 supports a plurality of turns of cable-core 16. The core 16 has a copper conductor 17, oil-saturated paper-tape insulation 18 and a skid-wire 19, and it is essential to maintain the insulation free from any moisture that may enter the package. For this reason the reel is covered between the ilanges 12, 13 with an impervious flexible cover 20 of foil-backed cloth or similar impervious material clamped against the sides of the flanges by clamping rings 21, 22. In its shipping condition the reel 11 is lagged with Wooden lags 23 held on by steel straps 26, 27 in a known manner. Under the cover 20 I tie a plurality of long, sausageshaped porous bags 28 of silica gel or other drying agent which is inexpensive and has a high moisture capacity at high humidity but a low moisture capacity at low relative humidity. The moisture capacity of silica gel, for example, is less than 10% by weight at 5% RH. and 25 C. In addition to the containers 23 I attach another sausage-shaped container 29 containing a desiccant with a high moisture capacity at low relative humidity. The containers 28, 29 are tied over the core 16 by suitable straps 30. A suitable drying agent for the bag 29 will have a moisture capacity greater than 15% by weight at 5% R.H. and 25 C.y Such an agent is crystalline aluminosilicate also known as molecular sieve. The bag 29 is sealed from moisture by being wrapped in a length of aluminum foil 31 folded lengthwise at 32 tightly enough to exclude moisture. Under the foil wrap 31 the bag 29 has a porous cloth wall 33 and between the wall 33 and the foil 31 I have inserted a strong cloth tape 34 running the length of the container 29. The cloth.tape 34 constitutes a ripcord that will tear through the foil 31 when it is pulled, and it will be understood that although I prefer a wide cloth for my ripcord because it will cause a greater area of the permeable wall 33 to be exposed I do not wish to be limited thereto and almost any strand of suiicient strength might be used for the tape 34. The end of the ripcord 34 is connected to a strand 36 which passes through a threaded hole 37 in the ilange 12. A threaded plug 38 is used to seal this hole after the ripcord 34 has been pulled by means of the strand 36.

3 Method The method of applying my invention is as follows: The cable core 16 is wound on the reel 11 and the containers 23 and 29 are tied over them by means of the straps 30. The cover 20 is then fastened in tight engagement with the flanges 12, 13 and the lags 23 strapped on. Thereafter the hole 37 is connected to a source of dry gas which can be passed into the package as long as it is retained in storage. When the reel is about to be shipped, however, the hole 37 is disconnected from the source of dry gas, the strand 36 is pulled to cause the ripcord 34 to open the foil 31 and the plug 38 is inserted to seal the hole. By this means the more sensitive desiccant in the container 29 is protected during the storage period when it is not needed because dry gas is available to be passed into the package. During shipment, however, which may take several days, no dry gas supply is available and it is at this time that my invention maintains a very low humidity in the package.

I have invented a new and useful package and method for which l desire an award of Letters Patent.

I claim:

1. A package for shipping moisture-sensitive material comprising:

(A) a substantially moisture-tight covering surrounding said material,

(B) a quantity of a irst drying agent within said covering,

(a) said first drying agent having a moisture capacity less than 10% by weight at 5% RH. and 25 C.,

(C) a lesser quantity of a second drying agent, separated from said rst drying agent, within said covering,

(a) said second drying agent having a moisture capacity greater than 15% by weight at 5% RH. and 25 C.,

(D) a substantially moisture-tight container for said second drying agent, and

(E) means for opening said container without removing said covering.

2. The package of claim 1 wherein said first drying agent is silica gel.

3. The package of claim l wherein said second drying agent is crystalline aluminosilicate.

4. A shipping package for oil-saturated electric cable cores comprising:

(A) a cable reel having opposing anges,

(B) a substantially moisture-tight cover sealing the space between said flanges,

(C) a moisture-permeable container holding a quantity of a first drying agent within said cover,

(a) said first drying agent having a moisture capacity less than 10% by weight at 5% RH'. and 25 C., (D) a substantially moisture-tight container holding a 5 quantity of a second drying agent within said cover, (a) said second drying agent having a moisture capacity greater than 15% by weight at 5% RH. and 25 C., and

(E) means for opening said moisture-tight container without removing said cover.

5. The package of claim 4 wherein said first drying agent is silica gel.

6. The package of claim 4 wherein said second drying agent is crystalline aluminosilicate.

7. A shipping package for oil-saturated electric cable cores comprising:

(A) a cable reel having opposing flanges,

(B) a substantially moisture-tight cover sealing the space between said anges,

(C) a moisture-permeable container holding a quantity of a rst drying agent within said cover,

(a) said drying agent having a moisture capacity less than by weight at 5% R.H. and 25 C.,

(D) a substantially moisture-tight container holding a quantity of a second drying agent within said cover,

(a) said second drying agent having a moisture capacity greater than by weight at 5% RH. and 25 C.,

(E) a ripcord for opening said moisture-tight container,

(F) a perforation in one of said flanges for the passage of said cord whereby said moisture-tight container can be opened without removing said cover, and

(G) means for sealing said perforation.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Modern Packaging, article by Hendel and Burr, January 1955, pp. 121-124. 

1. A PACKAGE FOR SHIPPING MOISTURE-SENSITIVE MATERIAL COMPRISING: (A) A SUBSTANTIALLY MOISTURE-TIGHT COVERING SURROUNDING SAID MATERIAL, (B) A QUANTITY OF A FIRST DRYING AGENT WITHIN SAID COVERING, (A) SAID FIRST DRYING AGENT HAVING A MOISTURE CAPACITY LESS THAN 10% BY WEIGHT AT 5% R.H. AND 25*C., (C) A LESSER QUANTITY OF A SECOND DRYING AGENT, SEPARATED FROM SAID FIRST DRYING AGENT, WITHIN SAID COVERING, (A) SAID SECOND DRYING AGENT HAVING A MOISTURE CAPACITY GREATER THAN 15% BY WEIGHT AT 5% R.H. AND 25*C., (D) A SUBSTANTIALLY MOISTURE-TIGHT CONTAINER FOR SAID SECOND DRYING AGENT, AND (E) MEANS FOR OPENING SAID CONTAINER WITHOUT REMOVING SAID COVERING. 